This invention relates to a transgenic mouse model exhibiting chronic CRF hypersecretion. These animals express high levels of ACTH and corticosterone throughout their life span and develop phenotypic changes consistent with Cushing's disease and anxiety due to excess glucocorticoid production. Consequently, the invention transgenic mice are useful for a variety of applications, e.g., to screen for compounds that can modulate in-vivo CRF levels, and the like.